SINGAPORE - President Donald Trump reprised his criticism of Canada's prime minister here Tuesday, threatening that Justin Trudeau's tough exchanges with him over trade policy would "cost a lot of money for the people of Canada."

Trump said he departed the Group of Seven summit that Trudeau hosted in Quebec late last week on "very friendly" terms with his six counterparts, including the leaders of France, Germany, Italy, Japan and Britain.

"When I got on to the plane, I think that Justin probably didn't know that Air Force One has about 20 televisions," Trump said. "And I see the television, and he's giving a news conference about how he will not be pushed around by the United States. I say, push them around? We just shook hands. It was very friendly."

Trump said he was retaliating against Canada with countervailing tariffs, saying of Trudeau: "He learned that's going to cost a lot of money for the people of Canada. He learned."

Trump made his comments in a wide-ranging news conference in Singapore following his historic summit with North Korean leader Kim Jong Un.

Trump was asked about the contrast between the respect he accorded Kim here Tuesday and the hostility he showed Trudeau in recent days, and what he would say to those who worry he is treating America's longtime friends, such as Canada, as enemies and its longtime enemies, such as North Korea, as friends.

"I think it's a very fair question," Trump said. "I had a very good meeting with the G-7. And I left the meeting, and I'll be honest, we're being taken advantage of by virtually every one of those countries very seriously."

Trump said a photograph released by German Chancellor Angela Merkel's spokesman that went viral captured a friendlier mood than what the snapshot conveyed to many analysts.

"The picture with Angela Merkel, who I get along with very well, where I'm sitting there like this" - Trump said, crossing his arms - "that picture, I'm waiting for the document because I wanted to see the final document."

Trump continued: "It was very friendly. I know it didn't look friendly; it was reported as nasty both ways, I was angry with her - actually, we were just talking, the whole group, unrelated to everything, very friendly, waiting for the document to come back."